Saying no and sticking to it used to serve Cambridge well. A righteous devotion to “no’’ in the late 1960s and early 1970s blocked a monstrous highway that would have plowed through the middle of Central Square. Absolutism saved the city once. But it won’t work twice.

A group of residents is currently pushing measures to stymie new real estate development around Central Square. The residents are trying to down-zone the area, and have already succeeded in putting a pair of planned construction projects on the shelf. They’re doing all this in the name of preserving Central Square. That’s a problem, because Cambridge residents can’t just wish the real estate market away. They can stand by and get steamrolled, or they can harness development as a tool for creating broad public goods. “No’’ isn’t an option.

Down-zoning — shrinking the size of a building a developer has the right to build — is an extreme proposition anywhere. It’s doubly radical in a place like Cambridge, a city of 100,000 and one of the densest municipalities in the state. Artificially low zoning is normally a suburban tool for keeping growth out; in Cambridge, it’s a bid to freeze things in place, to draw a line around Central Square’s neighborhoods and use that line as a shield against gentrifying forces.

The city unleashed this movement on itself. In December 2010, the commercial developer Forest City Enterprises submitted plans to build a large laboratory and office complex on Massachusetts Avenue, above the shuttered Cambridgeport Saloon. The city encouraged Forest City, the builder of a number of commercial properties between Central and Kendall squares, to pair its Massachusetts Avenue lab project with housing. The developer obliged, unveiling plans for a 14-story residential building that would rise a block away from its new lab. The housing tower aroused intense opposition from some Central Square residents, so Forest City backed away from it; a second group then criticized the lab plan for lacking a housing component. Paralyzed by the back-and-forth, the City Council opted to sit on its hands and let the zoning application on Forest City’s commercial project expire.

Opposition to the Forest City housing tower has mushroomed into a wider movement to curtail development across the city. Antipathy toward a single residential project became a petition to lower zoning across Central Square, and a bid to freeze any up-zoning efforts for a year. Both of these efforts stand in opposition to a city-funded planning process that is considering ways to add thousands of new housing units around Central Square to Cambridge’s development pipeline. Goody Clancy, the city’s planning consultant, is talking about auctioning off publicly owned parking lots around Central Square to kick-start a new wave of residential development. These parking-to-housing developments would need flexible height allowances to succeed.

The Goody Clancy planning study and the new anti-development faction both speak in the same language. They both talk about wanting to keep Central Square lively, diverse, and independent. The anti-development effort tries to take a stick to gentrification — the hope is that, by stalling development, they can freeze change out of the square. But the market doesn’t work that way. There’s already intense upward pressure on Central Square’s real estate values. The demand for living in urban neighborhoods like Central Square is rising exponentially, so zeroing out new development and putting a lock on the supply of apartments, condos, and storefronts will only drive prices higher and price out the very people the anti-development effort says it wants to retain.

The safety valve lies not in opposing development, but encouraging it, and then socializing it. The city can take advantage of high real estate values and harness them for community benefits. It can trade extra height in new developments for more aggressive affordable housing programs and subsidized rent for independent retailers. Builders are willing to make those trades, because they sustain the sort of vibrant urban neighborhoods that their developments are predicated on in the first place.

Residents of the city can’t just wish the real estate market away.

Kendall Square is a far livelier place to live now than it was a decade ago because its neighbors learned to encourage the sorts of development that benefit them. The residents around Central Square are in an even stronger position, since the lots that will fuel the neighborhood’s next building wave are publicly owned. But first, they have to learn how to put conditions on their yeses, instead of starting and ending with no.

Paul McMorrow is an associate editor at CommonWealth Magazine. His column appears regularly in the Globe.